Gibson's new Mastertone line of banjos debuted
in 1925, the year this PB-4
was made. Style 4 was the second
model up in the Mastertone lineand in the first year
of issue specifications included a ball-bearing tone ring,
mahogany neck and resonator,
two concentric rings of black and white purfling on the back
of the resonator, two-piece
flange, nickel plating, Presto tailpiece, fiddle-shaped peghead,
hearts and flowers inlay, and Brazilian rosewood
fingerboard.

Gibson Mastertones from 1925 are
readily indentifiable by two features unique to that year: The ball-bearing tone
ring has holes on the outside and the Mastertone logo appears on the peghead rather than the fingerboard.

The inside of the resonator bears the
signature of Earnest Ray, the original owner of this banjo who played it
professionally in the 1920s and 1930s.